Amino acids, proteins and DNA

Question 1

What are the side effects of Cisplatin?

Answer 1

prevent normal cells from multiplying
kidney damage
nerve damage

Question 2

Recall the mechanism of action of Cisplatin.

Answer 2

• Attaches to 2 guanine bases on a strand of DNA by ligand substitution
• N on the bases substitute Cl
• Hence, DNA strands cannot underwind to replicate so cancerous cells cannot multiply

Question 3

Explain why only one enatiomeric form of a substrate can bind to a stereospecific active site.

Answer 3

Only substrate molecules with the right shape and correct positions of functional groups can fit and bind to the active site - called the lock and key

Question 4

How can computers be used to help design inhibitor drugs?

Answer 4

Computer modelling can predict the shape of enzymes and substrates

Question 5

How can drugs act as enzyme inhibitors?

Answer 5

Mimick shape of the substrate
Bind to the active sites and hence prevent substrate from binding

Question 6

What is a stereospecific active site?

Answer 6

Only 1enantiomeris able to bind with the enzyme.

Question 7

Recall 2 properties of zwitterions.

Answer 7

White solids with high mpts
Soluble in water

Question 8

In what form do amino acids exist at pH 7?

Answer 8

Exist as zwitterions
Dipolar ion formed when AAs react with themselves